The reliance upon magnetic storage medium for storing confidential information is increasing exponentially. Magnetic storage can be used to store financial information, company trade secrets, top level government security information, and so forth. The ability for any unauthorized person to read such materials could be most damaging. Thus, the need to erase information from magnetic storage medium has become of paramount importance.
Magnetic tape or tracks on a magnetic disc can be erased by degaussing the magnetic media. Degaussing can be accomplished by applying magnetic fields of opposite polarity across the magnetized material. Hard drives are of particular interest as they are magnetic memory discs used in most every computer and are capable of storing gigabytes of information. While it was commonplace to repair computers when they failed, technological advances has made repair uneconomical and most computers are simply discarded should a failure occur. Data is transferred from the failed computer to the new computer, and the failed computer discarded. The hard drives may, or may not be removed, and the information stored thereon must be erased. Various devices employed to erase the information stored on hard drives by degaussing them are not known to obtain reliable and complete erasure of the information contained on the hard drive.
The complete destruction of the hard drive, including heads and coils has become paramount to the proper disposal of computers. However, these hard drives can be the most difficult to degauss to remove the information contained thereon. The prior art systems using permanent magnets do not address the problems of hard drive components that are not readily accessible, due to such factors as the sealing of the hard drive disk and/or head within an enclosure. In order to properly erase U.S. Government classified magnetic media having a high coercivity magnetic media, erasure in as many spatial planes as possible is necessary. Hard disc drives typically include magnetic coatings rising past hard coercivities of 3000 Oersteds.
Prior art magnetic information erasers utilize an iron core having coils wound thereon to create magnetic flux lines in a given direction. In order to obtain random orientation of the magnetic particles in the magnetic medium, either the magnetic medium or the iron core would need to be rotated. Electric current in winding portions beyond the ends of the iron cores can compensate for fringing effects, while prior art devices using permanent magnets do not counter the fringing effects.
U.S. Pat. No. 4,157,581, discloses an eraser for magnetic tape employing magnets that are spaced apart with complementing poles positioned in the same direction. The permanent magnets are aligned so that the facing magnetic poles are of like polarity. The poles are spaced apart and manually rotated while the magnetic material is slid between the magnets.
U.S. Pat. No. 4,286,295, discloses the use of permanent magnets placed on individual rotating discs. Each disc is rotated in a circular motion and the magnetic media can be placed on a casement, the device moves the spinning magnets forward and aft of the magnetic material to be degaussed.
U.S. Pat. No. 4,423,460, discloses a mechanism for erasing magnetic material using a rotating magnetic field. These are electromagnets causing magnetic field by placement of pole faces of each structure to oppose each other and are spaced by an air gap with sufficient width to receive a tape carrier. The tape carrier is drawn between the magnets to allow for the degaussing.
U.S. Pat. No. 4,551,782, discloses an apparatus for degaussing magnetic storage media wherein the magnetic material is placed within a drawer. Upon movement of the drawer, an axial magnetic field is created in alternating directions while the magnetic material is rotated.
U.S. Pat. Nos. 4,639,821 and 4,672,345 discloses a degausser that employs a conveyor belt that moves magnetic material across a rotating magnet. The magnetic field passes through a supporting surface and degausses articles placed on the supporting surface. The magnet is rotatable above its axis thereby providing corresponding reversing positions.
U.S. Pat. No. 5,132,860, discloses the use AC and DC type degaussing having magnet poles of the same polarity disposed opposite each other so that a bucking field is induced. A DC magnetic filed is produced as magnetic media is passed thru a gap between the magnets. AC erasure can be brought about through the movement of the magnet media through two or more opposite polarity fixed fields.
U.S. Pat. No. 5,666,413, discloses a scrambler of the magnetic media for reusable magnetic tapes such as that employed in a micro cassette recorder. The device includes an enclosure having a magnet placed thereon in a surface to prevent engagement of the device with the magnet wherein the slot in the device causes directional placement of the tape.
U.S. Pat. No. 5,721,665, discloses the use of an electromagnet bulk degaussing. This device includes a means for recovery of the mechanism used for transporting magnetic media should it stall due to magnetic interaction with the media and the magnets. This device addresses bulk degaussing systems that cause a stall in the transportation system due to the heavy magnetic pole required for proper degaussing.
U.S. Pat. No. 5,979,774, is a device for erasing magnetic displays by the use of a U-shaped style magnet having opposing complimentary magnetic poles. The U-shape magnet requires a magnetic display sheet to be placed between the poles for destruction thereof.
U.S. Pat. No. 6,714,398, discloses the use of a container replacement of magnetic material therein having magnets placed on each side of the container. The device employs fixed magnetic north-north poles predisposed and spaced apart from a complementary set of magnets arranged so that the poles of the adjacent magnet interact to counteract fringing effects.
Thus, what is lacking in the art is a degaussing apparatus having permanent magnets that are rotatably mounted and whose common center poles are aligned to obtain a flux level gauss of 2× or twice that of when opposite center poles are aligned. The rotatably mounted magnets are placed within a housing allowing placement of the items to be degaussed directly thereon.